1. Field of the Invention
The present invention pertains to a cranking device for use in cranking winch mechanisms. More particularly, the present invention pertains to a low torque cranking device for use in quickly and easily rewinding unloaded, industrial type winches, such as the winches conventionally used to secure loads on flatbed trailers.
2. Description of Relevant Art
Winches are conventionally known, as are cranking handles usable together with the winches. Typically the winch includes a rotatable shaft having a relatively long cable or strap wound thereon, a ratchet mechanism associated with one end of the shaft for selectively preventing the shaft from being rotated in a direction in which the cable or strap is unwound, and a crank or crank handle associated with the opposite end of the shaft for rotating the shaft in one or both directions, The crank or crank handle is conventionally required to be tightly fitted over or within the end of the winch shaft so that it can apply a sufficiently high torque to the shaft for rewinding the cable or strap when the cable or strap is loaded.
Some conventional winches, winch handles and crank handles are, for example, disclosed in U.S. Pat. No. 944,534 (Beaman); U.S. Pat. No. 2,464,941 (Rader); U.S. Pat. No. 4,338,827 (Hooker); U.S. Pat. No. 4,391,432 (Baud); Design Pat. No. 275,138 (Bacon); U.S. Pat. No. 4,674,355 (Klein); Design Pat. No. 292,550 (Jackson); U.S. Pat. No. 4,883,255 (Bacon); U.S. Pat. No. 5,255,573 (Estabrook); and U.S. Pat. No. 5,344,121 (Baziuk).
With reference to FIG. 4 of the present drawings, there is shown (together with a low torque cranking device according to the invention) an industrial type winch 100 such as conventionally provided on a flatbed trailer for securing loads on a trailer. The winch is constructed of heavy duty materials such as heavy gauge steel and includes a shaft rotatably supported by a bracket 102 that would be fixed to a trailer (not shown), a heavy duty nylon strap 104 which is 4-8 inches wide by 20-50 feet long and wound on the shaft, a ratchet mechanism 106 provided on one end of the shaft, and an enlarged hollow head 108 provided on the opposite end of the shaft. The hollow head is typically cylindrical in shape and includes a plurality of openings 110 (typically four or six) defined through a side wall thereof and which are shaped to snugly receive the end of an elongate bar or rod (not shown) therethrough such that the bar or rod extends perpendicularly to a longitudinal axis of the winch shaft. In use, the nylon strap will be unwound from the winch, laid over a load disposed on the trailer bed, the free end of the strap is secured on the opposite side of the trailer from the winch, and the winch is cranked using the elongate bar so as to tighten the strap about the load. When the elongate bar is fitted to the enlarged head of a winch shaft, an operator can apply a relatively large cranking torque to the winch shaft, which is necessary for adequately tightening the nylon strap about the load, because significant leverage is established due to the length of the bar.
On the other hand, after the nylon strap has been released from a load the elongate bar cannot practically be used for rewinding the unloaded strap onto the winch shaft due to the significant length of the bar. Particularly, each time the bar is cranked to rotate the winch shaft through a certain angle, such as 90.degree.-180.degree., the end of the bar would have to be removed from an opening of the shaft head, and inserted in a different opening, and this process would have to be repeated until the strap is fully rewound. Such process of repeatedly inserting, rotating and removing the elongate bar is simply too tedious and time consuming so that operators have conventionally not used the elongate bar to rewind the unloaded strap, and instead have simply resorted to cranking the winch shaft by hand so as to rewind the nylon strap. Such hand cranking of the winch shaft is less tedious and time consuming than using the elongate bar, but it is still not very fast and somewhat tedious.
Moreover, with use of the industrial type winches over a long period of time, as is normal given their industrial-type construction, metal burrs are created by the elongate bar in the side wall of the enlarged crankshaft head around the openings where the bar is inserted through the head and cranked. Such burrs are a hazard if contacted directly by an operator's hand, and otherwise become larger and more numerous the more the winch is used.
The present invention has been developed to overcome the problems and disadvantages of known winches and winch handles as discussed above, and to generally fulfill a great need in the art for a simple mechanism which may be used with conventional industrial-type winches of the discussed type for conveniently and rapidly rewinding an unloaded winch strap or cable.